Nikon Corporation

Mitsubishi Denki Kabushiki Kaisha

Hideaki Shimonura

Tetsuo Hattori

Masaaki Kusano

Yuji Manabe

Atsushi Sekine

Apparatus are disclosed that provide a high-luminance projected image with no color shading or uneven contrast. Light from a light source undergoes color separation by passing through a color-separation optical system (e.g., a cross-dichroic mirror or cross-dichroic prism). The light from the light source can also be split into first and second polarized lights by passage through, e.g., a first polarized-light beamsplitter (PBS). Each color-separated light is modulated by a respective color-signal light valve and undergoes color combining by, e.g., a cross-dichroic prism. The second polarized light, if formed, is modulated by a luminance-signal light valve, undergoes color combining and polarized-light combining by, e.g., a second PBS, and is projected by a projection lens (that comprises an aperture stop). The PBSs, cross-dichroic mirrors, and cross-dichroic prisms are situated where principal rays (defined by the aperture stop) are parallel to the optical axis. The first PBS (if present) and color-separation optical system are preferably arranged between a front illumination lens group and a rear illumination lens group both comprising an illumination relay optical system telecentric on both front and rear sides thereof. Field lenses and relay lenses can be included that comprise a relay optical system forming a magnified image of the color-signal light valves at a position conjugate to the luminance-signal light valve with respect to the projection lens.

Projection-display apparatus

Apparatus is disclosed that provides a high-luminance projected image with no color shading or uneven contrast. Light from a light source undergoes color separation by passing through a color-separation optical system (e.g., a cross-dichroic mirror or cross-dichroic prism). The light from the light source can also be split into first and second polarized lights by passage through, e.g., a first polarized-light beamsplitter (PBS). Each color-separated light is modulated by a respective color-signal light valve and undergoes color combining by, e.g., a cross-dichroic prism. The second polarized light, if formed, is modulated by a luminance-signal light valve, undergoes color combining and polarized-light combining by, e.g., a second PBS, and is projected by a projection lens (that comprises an aperture stop). The PBSs, cross-dichroic mirrors, and cross-dichroic prisms are situated where principal rays (defined by the aperture stop) are parallel to the optical axis. The first PBS (if present) and color-separation optical system are preferably arranged between a front illumination lens group and a rear illumination lens group both comprising an illumination relay optical system telecentric on both front and rear sides thereof. Field lenses and relay lenses can be included that comprise a relay optical system forming a magnified image of the color-signal light valves at a position conjugate to the luminance-signal light valve with respect to the projection lens.

Growing community of inventors

Kawasaki, Japan

Hideaki Shimonura